Linear function

In mathematics, the term linear function refers to two distinct but related notions:^[1]

In calculus and related areas, a linear function is a function whose graph is a straight line, that is, a polynomial function of degree zero or one.^[2] For distinguishing such a linear function from the other concept, the term affine function is often used.^[3]
In linear algebra, mathematical analysis,^[4] and functional analysis, a linear function is a linear map.^[5]

^ "The term linear function means a linear form in some textbooks and an affine function in others." Vaserstein 2006, p. 50-1
^ Stewart 2012, p. 23
^ A. Kurosh (1975). Higher Algebra. Mir Publishers. p. 214.
^ T. M. Apostol (1981). Mathematical Analysis. Addison-Wesley. p. 345.
^ Shores 2007, p. 71